80% AR10 Lowers

I have been drooling over a couple of the 80% kits for about a year now. Until recently, I did not have a drill press that I trusted to be accurate enough even with a good jig. But I solved that problem a couple weeks ago with a big monster Powermatic. So, maybe this year?

Meangreen said:

I have been working on some 80% AR15 receivers and I say receivers because I have screwed up a couple. I have a machinist friend of mine helping me out but it's wicked hard work. I found really nice kits from centerfiresystems.com and what I'm trying to build is a Vietnam era replica A1.

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Other than the obvious jig with the templates, do you need any special toolings to machine them?

I did find a couple places that sell trigger groups already assembled, so all you have to do is set them in and add a couple screws rather than dealing with assembling all of the spring and goofy other parts. I think if I can get it that far, the rest should be easy.

inceptor said:

Got mine from here

Polymer80 | AR Polymer 80% LowersPolymer80 - AR Polymer 80% Lowers | Polymer80

Still in the safe, haven't had time to touch it yet. The do offer a guarantee if you mess it up, they will replace it. So I figured I would give them a try. Now they have video instructions too. I'm more of a visual kinda guy.

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That looks like a better kit to start with! I was looking at these guys:

Home - Ares Armor

They are made from Billet aluminum. So, I am guessing they are higher quality. But the jig is also about $100 (but is reusable). I think I will eventually try one of them. But as a first step to get the process down, the polymer one looks like it would be perfect.

My experience working with plastics is that you can use any tools that you would normally use on wood. The kit that Interceptor posted does also include the necessary bits as well as an end mill. I expect for $20 they are not the greatest quality, but I should think if you are careful and work slowly, you should be able to do it without too much problem.

Interceptor - Please post your thoughts on the process. If yours works well, I think I am going to try a polymer one first.

inceptor said:

The way things are going here, I can promise that I won't get to it until after the new year.

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I am half tempted to go buy one now, but starting Tuesday, I am booked solid until Christmas. I'll think on it for a few days, but this would make a fun project over the Christmas break...

jimb1972 said:

I dont have a mill, but I do have a lathe. Anyone try chucking an endmill in a lathe and mounting something to the tool holder? If so did it work?

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A metal lathe would certainly work although you would have to plan your cuts at 90 degrees. That might be a bit tricky.

I cannot think how you would get the accuracy you would need with a wood lathe. I guess you could make some kind of fixture to mount on the hole for the tool rest? Before I would do that however, I would think about making a jig to hold the lower and machine it with a router. From the video that Interceptor posted, all of the holes and cuts you need to make are using standard sizes. So a few spiral downcut router bits might actually do the job. Although, the slowest any of my routers will go is 10,000 RPMs. That might be too fast?

As for me, I just got a new drill press from hell and have been looking for projects to use it. So, this is a perfect one. I will not get to it for a while, but I will post on how it goes.

jimb1972 said:

The reason I asked about the lathe (metal) is because I am not sure how well a drill press will stand the side loads of an end mill, would you pm me when you get to it so I don't miss your report of the results?

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You bet.